sniper

sniper
    n 1: a marksman who shoots at people from a concealed place
    

39 Moby Thesaurus words for "sniper":
      Nimrod, Zouave, archer, artilleryman, bersagliere, bowman,
      cannoneer, carabineer, chasseur, crack shot, dead shot, deadeye,
      dogface, doughfoot, expert rifleman, foot soldier, footslogger,
      fusileer, good shot, grenadier, grunt, gun, gunman, gunner, hunter,
      infantryman, light infantryman, marksman, markswoman, musketeer,
      paddlefoot, rifle, rifleman, sharpshooter, shooter, shot,
      targetshooter, toxophilite, trapshooter